1  /* Copyright (C) 1997-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #ifndef _SYS_POLL_H
      19  # error "Never use <bits/poll.h> directly; include <sys/poll.h> instead."
      20  #endif
      21  
      22  /* Event types that can be polled for.  These bits may be set in `events'
      23     to indicate the interesting event types; they will appear in `revents'
      24     to indicate the status of the file descriptor.  */
      25  #define POLLIN		01              /* There is data to read.  */
      26  #define POLLPRI		02              /* There is urgent data to read.  */
      27  #define POLLOUT		04              /* Writing now will not block.  */
      28  
      29  #if defined __USE_XOPEN || defined __USE_XOPEN2K8
      30  /* These values are defined in XPG4.2 and later.  */
      31  # define POLLRDNORM	POLLIN		/* Normal data may be read.  */
      32  # define POLLRDBAND	POLLPRI		/* Priority data may be read.  */
      33  # define POLLWRNORM	POLLOUT		/* Writing now will not block.  */
      34  # define POLLWRBAND	POLLOUT		/* Priority data may be written.  */
      35  #endif
      36  
      37  /* Event types always implicitly polled for.  These bits need not be set in
      38     `events', but they will appear in `revents' to indicate the status of
      39     the file descriptor.  */
      40  #define POLLERR         010             /* Error condition.  */
      41  #define POLLHUP         020             /* Hung up.  */
      42  #define POLLNVAL        040             /* Invalid polling request.  */